Belle II Technical Design Report

The Belle detector at the KEKBelectron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super- KEKB, an upgradeof KEKBis under construction, to increase the luminosityby two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgradeof the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.